Exceptional local and global collaboration delivers the new PRISMA 2020 statement

Today is an auspicious day for a dedicated global team of methodologists, search specialists, biostatisticians and systematic reviewers who have spent the last few years diligently updating PRISMA - the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. First published in 2009, PRISMA was designed to help systematic reviewers transparently report why the review was done, what the authors did, and what they found. 

While this may sound simple, it is anything but. Systematic reviews are complex, using an array of methods from the identification of studies through to the synthesis of results, and careful reporting is required so that users of the review (such as guideline developers, policy makers, healthcare providers and patients) are able to understand what was done and how the findings might apply to them.

The updated open-access PRISMA statement is available online and published in no less than five leading journals - including BMJ, PLOS Medicine, Journal of Clinical Epidemiology, Systematic Reviews and International Journal of Surgery. It represents a major global collaborative effort which was sustained throughout the many challenging months dominated by COVID-19 throughout 2020. The project had strong representation from Monash University's School of Public Health and Preventive Medicine, with co-leads Matthew Page and Joanne McKenzie (and David Moher, Ottawa Hospital Research Institute) and contributors Sue Brennan and Steve McDonald. This representation reflects the calibre of systematic review expertise within the School - with specialisation in methods for bias, statistics, certainty of the evidence (GRADE) and searching.

‘This was such a rewarding experience thanks to the enthusiastic input, detailed deliberations and expert contributions from both our local team and fellow researchers around the world,’ lead author Matthew Page explains. ‘The updating process involved lengthy consultation and a comprehensive survey of systematic reviewers, journal editors and methodologists with experience with and interest in the use of the previous iterations of PRISMA.’

‘We obtained a lot of valuable feedback via our initial survey. In addition to answers to more straightforward multiple choice questions, we also collated over 100 pages worth of collective free text comments from respondents who felt really passionately about particular reporting elements, and specified what they thought should or shouldn’t be included in the updated guideline. We had this wealth of feedback to draw on and discuss at our two day workshop at the Cochrane Colloquium in Edinburgh back in 2018, which was fantastic. A healthy degree of consensus emerged from that, followed by much drafting, redrafting and careful considerations around the clarity of language used to update existing and outline new recommendations. This was followed up by piloting with authors to get their feedback and incorporate a final round of changes.’ 

Joanne McKenzie played a critical role throughout this process, co-facilitating the development meeting and processing the meeting notes, developing the updated guideline structure and overseeing the inclusion of guidance on new statistical developments that have been introduced in the decade since the original PRISMA statement was released. 

‘We know systematic reviews are essential for healthcare providers, policy makers, and other decision makers, who would otherwise be confronted by an overwhelming amount of research to guide their decisions,’ Joanne says. ‘We really wanted to make this a practical, accessible and contemporary checklist both for systematic reviewers and for the many different users who depend on them. As such, we included detailed information about why reporting of each item is recommended along with plenty of examples from published reviews.’ 

‘We’re hopeful that these kinds of changes and additions to PRISMA 2020 will encourage greater uptake of the guideline and lead to more transparent, complete and accurate reporting of systematic reviews around the globe. There are plenty of positives in that for everyone.’ 

In a study Matthew Page and colleagues conducted on Reporting Characteristics of Systematic Reviews in PLOS Medicine back in 2016, around 29% of authors explicitly reported that they used the PRISMA Statement to guide either the conduct or reporting of their review, and all those who worked on this update are hopeful this number will continue to rise. 

‘Looking ahead, we’ll continue to work together to plan and design interventions and software to help with future implementation,’ Joanne concludes. ‘We’re keen to evaluate both the use and usability of PRISMA 2020 in the months and years to come, so while we’re excited about the launch today it’s definitely part of a bigger picture plan to support and encourage more accurate and complete reporting of systematic reviews now and into the future.’ 

PRISMA workshop Edinburgh 2018

Photo: PRISMA workshop participants, Cochrane Colloquium, Edinburgh 2018

Article published: 30 March 2021